It would be nice to be able to "hold" a command on so it can be used multiple times without having to select it each time. I would suggest that double clicking on a command would hold it. As an example, currently if I want to make multiple new axis I will select the axis tool, use it, select the axis tool again, use it, and so on. If you could hold a command on, you would double click the axis tool, make as many axis as you need, then hit esc (so select another tool) to exit from using the axis tool.